[Photo 8 of Weller's book] Fragment of drawing 1174, the south elevation of the future Krematorium II, with a cross-section of Leichenkeller 1.

Translation of notes

8. Elevation of the Krematorium with, in the foreground, the cross-section
of the cellar. The ventilation ducts can be seen on the sides.

9. Cross-section of the two “corpse cellars”.

The first is the gas chamber: note the air extraction duct (Entlüftungskanal) on each side of the drawing. Above, also each side, the ventilation duct (Belüftung). At the end is the entrance door. In the second “corpse cellar” ("undressing room") there is no ventilation or air extraction duct.